Burner assembly



Sept. 27, 1966 B. J. MOORE 3,275,245

BURNER ASSEMBLY Filed Aug. 21, 1964 5 Sheets-Sheet 1 INVENTOR.

BENNETT J. MOORE ATTORNEYS 3 Sheets-Sheet 2 INVENTOR- BE/Y/VETT J. MOOREB. J. MOORE BURNER ASSEMBLY Sept. 27, 1966 Filed Aug. 21, 1964 flnfv/dcATTORNEYS Sept. 27, 1966 B. J. MOORE 3,275,245

BURNER ASSEMBLY Filed Aug. 21, 1964 3 Sheets-Sheet 5 FIG.5

x INVENTOR. v BENNETT J. MoaRE 6 L BY ATTORNEYS United States Patent3,275,245 BURNER ASSEMBLY Bennett J. Moore, Detroit, Mich., assignor toMagic Servant Products Company, Detroit, Mich, a corporation of MichiganFiled Aug. 21, 1964, Ser. No. 391,140 20 (Ilaims. (Cl. 239-399) Thisinvention relates to heating units and more particularly has referenceto an improved burner construction for such a unit.

In many conventional burner assemblies, air supplied from the blowerunit is split into primary and secondary airstreams. The primary air ismixed with the gas and directed to the pilot unit for combustion withinthe combustion chamber. The secondary air is directed to the combustionchamber where it mixes with the unburned gas in the primary airstreamproducing complete combustion of the gas, and causes the heated air torise in the combustion chamber.

An important problem associated with this type of burner is that ofadjusting the amount of air provided respectively in the primary andsecondary airstreams. When the burner is installed or adjusted the airintake at the blower unit is usually adjusted to vary the volume of airdelivered to the combustion chamber. In addition, the volume of airprovided respectively in the primary and secondary airstreams is alsomanually varied in order to produce complete combustion of the gas andthe proper movement of the heated air within the combustion chamber. Inother words, adjustment of the burner normally requires that the airflow be adjusted both at the blower intake and at the entrance to thecombustion chamber. This dual air adjustment considerably complicatesinstallation or adjustment of the burner assembly.

As will be subsequently described in detail, in a preferred embodimentof the present invention a burner assembly is provided having an airsplitter member integral with the mounting plate fastening the burner tothe wall of the hearth or combustion chamber. The air splitter isadapted to provide a pre-set ratio of primary to secondary air flowregardless of the volume of air supplied from the blower. As a result,adjustment of the burner assembly requires adjustment of the air ilowonly at the intake of the blower unit.

The present invention is particularly suited as a conversion burner forexisting oil burners. A major problem associated with converting suchoil burners is that of providing the same amount of heat as was providedwith the oil burner in the existing combustion chamber space. Gasburners normally require more space than oil burners to produce the samequantity of heat and consequently conversion units heretofore in usehave been inefiicient, expensive and hence inadequate for mostinstallations. In addition, these conversion units are frequentlycharacterized by unpleasant noise and pulsations.

The present invention provides means for spinning the primary gas-airmixture and upshot firing of this mixture in the hearth while thesecondary air is directly fired or inshot into the chamber. As a result,noise and pulsation are substantially eliminated and the burner iscapable of operating in a combustion chamber of smaller size than thatrequired for conventional gas burners. I have found that my gas burnerrequires a combustion chamber with only 25% of the volume presentlyrequired for available gas burners. My burner will develop the sameamount of heat as the replaced oil burner, in the same combustionchamber, and without noise or pulsation.

The one-piece splitter and mounting plate permits the entire burner tobe of a far more compact and simple construction than is possible Withconventional burners.

ice

In addition, while most burners employ a Venturi or similar structurewithin the conduit carrying the primary air and gas, I employ a battlewithin the conduit adjacent the gas inlet which provides turbulence inthe air-gas flow stream and permits the conduit to be of considerablyshorter length than that required when a Venturi is employed. Thisfeature, along with those mentioned above, permits the burner to operatewithin a hearth of considerably smaller size than that required forconventional burners of the same capacity.

It is accordingly an object of the present invention to provide a burnerassembly of simple and compact design adaptable for use with furnaceshaving relatively small combustion chambers.

Another object of the present invention is to provide a conversion gasburner assembly adapted to operate in the same combustion chamber as theoriginal oil burner, at the same capacity, and without noise orpulsation.

Another object of the present invention is to provide a burner assemblyin which a pre-set ratio of primary to secondary air is providedregardless of the volume of air delivered by the blower.

Still another object is to provide a burner assembly of this kind whichis of simple construction and of low manufacturing cost.

Other objects and advantages of the present invention as well as variousother novel features of the invention will be more readily apparent fromthe following detailed description of a preferred embodiment thereof.The description makes reference to the drawings in which:

FIGv 1 is an end elevational view of a burner assembly according to apreferred embodiment of the present invention;

FIG. 2 is a side elevational view of the burner assembly of FIG. 1;

FIG. 3 is a cross-sectional view taken along the lines 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along the line 44 in FIG. 2;

FIG. 5 is a detail plan view taken along the lines 55 in FIG. 2; and

FIG. 6 is a cross-sectional view taken along the lines 66 in FIG. 5.

Description Referring to the drawings in detail, the present burnerassembly is shown adapted for mounting on the hearth or combustionchamber wall 13 of a conventional furnace as shown in FIG. 2. The burnerassembly includes a disc-shaped splitter member 10 having a peripherallyextending mounting flange 11 adapted to be mounted to the wall 13 and apair of parallel axially extending bosses 12 and 14 projecting from oneside as can best be seen in FIG. 4. The boss 12 surrounds a circular airinlet 16 while the boss 14 surrounds a smaller circular gas inlet 18. Athird boss 20 is provided on the opposite side of the splitter member 10as shown in FIG. 4 which is substantially coextensive with the gas inlet18 and with a portion of the air inlet 16. A gas conduit 22 fits withinthe boss 14 while a blower exhaust tube 24 is secured in the larger boss12 by means of tightening screw 26. A mixing or upshot tube 28 projectsinto the combustion chamber indicated generally at 15 in FIG. 2interiorly of the wall 13 and is secured in place in the boss 20 on theopposite side of the splitter member 10. The tube 28 includes a smallbaflle 30 which projects into the interior of the tube immediatelyacross from the gas inlet 18. A bafile 31 is secured to the mountingflange 11 by means of screws 33 and is disposed across a portion of theinlet 16. Thus gas introduced through the conduit 22 is directed intothe interior of tube 28 and strikes the baffle 30. Air delivered fromthe blower, which will be described in detail below,

through the splitter member 10 outside of the tube 28 and is deflectedor agitated by the baffle 31. The air and gas entering the mixing tube28 are thoroughly mixed due to the turbulence created by the baffle 30across the flow stream.

As can best be seen in FIGS. 1 and 2, the blower assembly 32 comprises amotor unit 34 adapted to drive a conventional blower unit 36. The airintake for the blower unit 36 is provided with a threaded bolt 38 onwhich a disc-shaped seat 40 is adapted to move axially. A nut 42threadably engages the bolt 38 and limits the outward movement of theseat 48 along the bolt. The seat 40 limits the volume of air pulled intothe interior of the blower unit 36; thus, by adjusting the position ofthe nut 42 and the seat 40 the volume of air pulled into the blower unit36 and hence delivered for combustion, may be controlled. The blowerunit 36 delivers air into the exhaust tube 24 where it is split, asdescribed above, the primary air moving into the mixing tube 28 and thesecondary air passing into the interior of the combustion chamber (notshown) externally of the mixing tube 28.

Gas is delivered to the burner through a gas intake tube 44 which isconnected through elbow 46 to a conventional valve member 48. The lattermember is adapted to direct a portion of the gas delivered from the gasdelivery tube 44 through a gas line 50 and an L-shaped valve member 52to -a T-shaped connector 56. The connector 56 directs a portion of thegas along a line 58 to another valve 60 which delivers the gas to aconventional perforated lighter tube 64 which extends through an openingin the splitter member 10. The outer end of the lighter tube 64 issupported on an L-shaped bracket member 66 which is rigidly secured tothe upwardly turned end of the mixing tube 28.

The connector 56 also directs gas through a line 68 to a central valvecontrol 70 which in turn directs the gas through a line 72 which extendsto a point opposite the face of the splitter member 10. The tube 72 isconnected, through a suitable mechanical connection, to a nut 74 whichis fixed within a hole in the splitter member 10. The opposite side ofthe nut 74 is connected to a pilot tube 76 which terminates at its outerend in a pilot assembly 78 of the conventional variety supported on thebracket 66 adjacent the lighter tube 64.

A thermocouple 80 extends from the central Valve member 70 through ahole in the splitter member 10 to a point adjacent the orifice of thepilot assembly 78 and is supported in place on the bracket 66.

The central gas tube 44 is connected through a conventional pressureregulator 82 and an elbow 84 to the interior of the central valvecontrol 70. The valve control 70 is actuated through an electricalcontrol unit 86 connected to a suitable source of electrical power (notshown). The electrical control unit 86 is connected to the central valvemember 70 through the cable indicated at 88 and into the blower assembly32 by suitable means (not shown).

A deflector or spinner 90 is provided at the upper outer end of themixing tube 28. As shown in FIGS. and 6, the deflector or spinner 90 isfluted, having a number of spaced inclined vanes or flutes 92 extendingradially outward from a central hub 94. The deflector 90 is cupshaped incross section as can best be seen in FIG. 6 with the vanes 92 disposedin concave fashion within the end of the mixing tube 28. The vanes 92are separated by radially extending strips 96 extending outwardly fromthe hub 94, each vane 92 being bent to form an angle with the plane ofthe strips 96 and to provide radially and circumferentially extendingopenings 98 therebetween. These openings 98 spin the air-gas mixture asit issues quired for the same capacity burner.

4 through the tube 28. The concave shape of the spinner causes thisissuing gas-air mixture to be concentrated at a point directly above thedeflector 90, for ignition by the pilot assembly 7 8. The spinner 90 isremovable from the end of the mixing tube 28 and, if desired, may beinverted so as to be convex upward. In such a case, the spinner 90 willact to spreadthe air-gas mixture outwardly as it issues from the mixingtube 28.

When installing the present burner assembly either as a conversion unitor in a new heating system, the splitter 10 is fastened across asuitable opening 17 in the wall 13 of the combustion chamber 15, asshown in FIG. 2. The configuration of the mounting flange 11 on thesplitter member 10 will depend upon the size and shape of the opening 17in the combustion chamber wall 13. In the splitter member shown in thedrawings, the mounting flange 11 is circular with regularly spacedrecesses 100 which are adapted to receive suitable bolts for securingthe splitter member 10 to the wall 13 of the combustion chamber 15.However, the shape of flange 11 will vary depending upon the hearth uponwhich it is to be mounted. When the splitter member is thus mounted inplace, the mixing tube 28, the lighter units 64, and the pilot assembly7 8, all project into the interior of the combustion chamber 15.

In operation, the present burner assembly is started in the conventionalfashion, by permitting gas to flow through gas line 58 to the lighterassembly 64 and lighting the lighter assembly 64 so that a flame isproduced at its outer end adjacent the end of the mixing tube 28. Thisflame heats the thermocouple 80 which in turn causes the central valvecontrol 70 to direct gas into the pilot gas line 72 and thence into thepilot assembly 78. The issuing gas at the end of the pilot assembly 78is ignited by the lighter assembly 64.

The air intake at the blower assembly 32 is adjusted by suitablypositioning the nut 42 and the seat 40. With each actuation from theelectrical control unit 86, the blower motor 34 causes air to be pulledinto the blower unit 36 and forced through the blower exhaust portion 24to the splitter member 10 where the air is split into the primary andsecondary air streams. Gas supplied from the gas line 44 through thepressure regulator 82 and the central valve control 70 is introducedinto the gas inlet tube 22 where it is directed against the bafiie 30disposed along the interior of the mixing tube 28. The bafiie 30 causesthe gas and primary air entering the mixing tube 28 to be agitated andthereby thoroughly mixed. The air-gas mixture issuing at the upper endof the mixing tube 28 is ignited by the pilot assembly 78. The baflie 31on the combustion chamber side of the splitter member 10 causes thesecondary air diverted into the combustion chamber to flow around themixing tube and thereby thoroughly fill the combustion chamber. Thissecondary air aids in the complete combustion of the gas issuing fromthe mixing tube 28, and causes the heated air to rise in the combustionchamber.

The mixing tube 28 is preferably, as shown in the drawings, of theupshot variety; however, in certain situations the tube may be straightwith the combustion occurring at one horizontal end. I have found thatby employing a splitter member of the type shown, together with thebaflies 30 and 31 a shorter mixing tube 28 may be employed than iscommonly used with burner assemblies of the present type. This enablesthe present burner assembly to be used as a conversion unit for existingfurnaces having relatively small combustion chambers. I have found thatthe present burner can operate in a hearth of one-fourth the size ofthat conventionally re- In addition, the present burner operates in thesame combustion chamber as the original oil burner, at the samecapacity, and without noise or pulsation.

With the present burner assembly a pre-set ratio of primary to secondaryair is obtained regardless of the volume of air delivered by the blowerassembly 32. As a result, each time the volume of air delivered from theblower assembly is varied, adjustment of the proportion of air in theprimary and secondary air streams is not necessary. This assurescomplete combustion within the furnace regardless of the efliciency orsetting of the the blower assembly.

It will be apparent to those skilled in the art to which this inventionpertains that various changes and modifications may be made withoutdeparting from the spirit of the invention or the scope of the appendedclaims.

I claim:

1. A burner assembly, comprising (a) an air blower assembly,

(b) a gas delivery line,

(c) a mixing tube disposed within the combustion chamber of a furnace,

(d) a splitter member mounted within an opening in the wall of saidcombustion chamber to receive said .air andgas respectively from saidblower assembly and gas line externally of said combustion chamber, saidsplitter member delivering said gas and a preset proportion of said airto said mixing tube regardless of the volume of air delivered from saidblower assembly, the remainder of said air being delivered to saidcombustion chamber externally of said mixing tube.

2. The burner assembly as set forth in claim 1 and including a bafflemounted within said mixing tube adjacent said splitter member andadapted to produce turbulence in said mixing tube, said turbulenceproducing rnixing of said gas and the air delivered to said mixing tube.

3. The burner assembly as set forth in claim 1 and including a batflemember in said combustion chamber adjacent said splitter member anddisposed externally of said mixing tube and adapted to deflect the airdelivered to said combustion chamber externally of said mixing tube.

4. The burner assembly as set forth in claim 1 and wherein said blowerassembly includes an air inlet, a threaded shaft extending through saidinlet, a seat adapted to move along said shaft, the position of saidseat determining the volume of air drawn through said inlet, and a nutmember threadably engaging said shaft and adapted to limit the movementof said seat along said shaft and thereby limit the volume of air drawnthrough said air inlet.

5. The burner assembly as set forth in claim 1 and including a deflectormember at the combustion end of said mixing tube, said deflector havinga plurality of deflecting vanes arranged in cup-shaped fashion acrosssaid end of said mixing tube.

6. The burner assembly as set forth in claim 5 and wherein saiddeflector member is removably mountable in said mixing tube in one oftwo positions, the first of said positions having said vanes extendingin concave fashion across the said end of said mixing tube, and thesecond of said positions having said vanes extendng in convex positionacross said end.

7. A burner assembly, comprising:

(a) an air blower assembly,

(b) a gas delivery line,

(0) a mixing tube disposed Within the combustion chamber of a furnace,

(d) a splitter member comprising a mounting flange securing said burnerassembly to the wall of said combustion chamber, a gas inlet receivinggas from a gas delivery line, an air inlet receiving air from saidblower assembly, said splitter member delivering said gas and a presetproportion of said air to said mixing tube regardless of the volume ofair delivered from said blower assembly, the remainder of said air beingdelivered to the interior of said combustion chamber externally of saidmixing tube.

8. The burner assembly as set forth in claim 7 and including a bafliemounted in said mixing tube opposite said gas inlet and adapted toproduce turbulence in the gas flowing from said inlet into said mixingtube, and to thereby mix said gas and said air delivered to said mixingtube.

9. The burner assembly as set forth in claim 7 and including a baflie insaid combustion chamber opposite said air inlet and disposed exteriorlyof said mixing tube, said baffle deflecting the air entering saidcombustion chamber externally of said mixing tube.

'10-. The burner assembly as set forth in claim 7 and wherein saidblower assembly includes an air inlet, a threaded shaft disposed withinsaid inlet, a seat adapted to move along said shaft, the position ofsaid seat determining the volume of air drawn through said inlet, and anut threadably engaging said shaft and limiting motion of said seat inthe direction away from said inlet, said nut thereby controlling thevolume of air entering said blower assembly.

'11. The burner assembly as set forth in claim 7 and including adeflector mounted at the combustion end of said mixing tube, saiddeflector comprising a plurality of radially extending deflector vanesdisposed in cup-shaped fashion across said end of said mixing tube.

'12. The burner assembly as set forth in claim 11 and wherein saiddeflector is removably mounted in said mixing tube in one of twopositions, in the first of said positions said vanes being disposed inconcave fashion with respect to said end of said mixing tube, in thesecond of said positions said vanes extending in convex manner acrosssaid ends of said mixing tube.

'13. The burner assembly, comprising:

(a) an air blower assembly,

(b) a gas delivery line,

(0) an iupshot mixing tube disposed within the combustion chamber of afurnace,

(d) a splitter member comprising .a mounting flange securing saidsplitter member within an opening in the wall of said combustionchamber, a gas inlet receiving gas from said delivery line, an air inletreceiving air from said blower assembly, an outlet on the side of saidsplitter member opposite to said gas inlet and air inlet, said outletdelivering said gas and a preset proportion of primary air from said airinlet to said upshot mixing tube regardless of the volume of airdelivered from said blower assembly, said outlet delivering thesecondary air to the interior of said combustion chamber externally ofsaid mixing tube.

14. The burner assembly as set forth in claim 13 and wherein said gasand air inlets comprise axially extending openings on the side of saidsplitter member away from said combustion chamber, and said outletcomprises a circular opening on the side of said splitter member facingsaid combustion chamber, said outlet being coextensive with at least aportion of said gas inlet and said air inlet.

15. The burner assembly as set forth in claim 13 and including a bafllein said mixing tube at said outlet and adapted to produce turbulence inthe gas entering said outlet from said gas inlet.

16. The burner assembly as set forth in claim 13 and including a bafflein said combustion chamber disposed externally of said mixing tube andadapted to deflect said secondary air as it enters said outlet.

17. The burner assembly as set forth in claim 13 and wherein said blowerassembly includes an air inlet, a threaded shaft extending adjacent saidinlet, a seat coextensive with said inlet and movable along said shaft,and a nut threadably engaging said shaft and adapted to limit the motionof said seat so as to limit the volume of air delivered through said airinlet to said blower assembly.

=18. The burner assembly as set forth in claim 13 and including aspinner at the combustion end of said mixing tube, said spinnercomprising a pluality of deflecting vanes arranged in cup-shaped fashionacross said end of mixing tube.

'19. The burner assembly as set forth in claim 13 and including aspinner at the combustion end of said mixing tube, said spinnercomprising a plurality of deflecting vanes arranged in cup-shapedfashion across said end of said mixing tube.

20. The burner assembly as set forth in claim 18 and wherein saidspinner is removably mountable in one of two positions in the first ofsaid positions said vanes extending in concave fashion across said endof said mixing tube, and in the second of said positions said vanesextending in convex fashion.

No references cited.

EVERETT W. KIRBY, Primary Examiner.

1. A BURNER ASSEMBLY, COMPRISING (A) AN AIR BLOWER ASSEMBLY, (B) A GASDELIVERY LINE, (C) A MIXING TUBE DISPOSED WITHIN THE COMBUSTION CHAMBEROF A FURNACE, (D) A SPLITTER MEMBER MOUNTED WITHIN AN OPENING IN THEWALL OF SAID COMBUSTION CHAMBER TO RECEIVE SAID AIR AND GAS RESPECTIVELYFROM SAID BLOWER ASSEMBLY AND GAS LINE EXTERNALLY OF SAID COMBUSTIONCHAMBER,